Experimental investigation on residual stresses in heavy wide flange QST steel sections

• Residual stresses were measured in high-strength heavy QST wide flange sections.
• Two section types were examined: the stocky HD 400 × 1202 and slender HL 920 × 1377.
• Both sections displayed compressive residual stress at the flange tips.
• Through-thickness measurements showed little deviation from surface measurements.
• From the experimental results a residual stress model was proposed.

This paper presents the experimental results of residual stress measurements conducted on heavy wide flange quenched and self-tempered (QST) steel sections which have been developed by ArcelorMittal under the proprietary name HISTAR (HIgh-STrength ARcelorMittal). These sections are often applied in high-rise buildings, trusses or offshore structures and combine high strength with good toughness and weldability. The experiments are part of a larger study to arrive at buckling curves for these members as they are currently not provided by the European code. Two different sections with flange thicknesses greater than 100 mm are investigated and two types are examined: the stocky HD and more slender HL type. The sectioning method is adopted for measuring the residual stresses. It is found that both types display compressive residual stresses at the flange tips and the web and tensile residual stresses at the web-to-flange junctions. In absolute sense the residual stresses are greater in the HL type. From the experimental results a residual stress model is derived which can serve as the initial stress state of a heavy HISTAR section in non-linear finite element analyses.